5k iMac reboots on it's own after installing 10.11.4

Hi, has anybody a solution for this issue. My 5k imac shows the exact same behavior since i updated to os x 10.11.4.It randomly stops and is rebooting itself. I already reinstalled 10.11.4, removed third party apps. But it's keeping rebooting (between 1 and 5 times a day). System.log shows no hints. When i am looking for "previous shutdown cause" it shows me also "-128".

I dont think this is a hardware problem, i guess it's a kind of a bug in os x 10.11.4.

Has anyone tried to get 10.11.3 reinstalled?

avoidwork,

Thanks for keeping us posted.

Did the Apple store give you options, if the issue persists?

Out of curiosity, did they wipe the partition before the reinstall of OS X or did they just initiate the reinstall over the existing?

Maybe someone else can chime in but I think if you don't wipe the partition in Disk Utility first it's just overwrites system files and leaves your files intact.

Could be wrong though.

Regardless, when they gave it back to you did it have all of your software on it or was its vanilla install?

Mine rebooted last night as well a few times.

I agree its a software issue, but has to be attached to something hardware related on the 5K iMacs. My MacBook Pro has zero issues with 10.11.4 and all kinds of third party apps.

Even through my hardware test came back clean, I'm wondering if it could be an issue with AMD drivers on our machines.

That's the only major thing hardware wise I can think of that's different, but unfortunately i believe "drivers" on OS X cannot be updated independently.

Hi,

thanks for your update. I just found the 10.11.3 Installer App on one of my USB-Sticks, that i created due to a reinstallation in 11-2015. I will try to reinstall my iMac with 10.11.3 this weekend and give you an update, wether i get this issue fixed with 10.11.3. I hope it will work, otherwise the iMac is also complete useless to me too 😟.

Gah,

I should have done that before updating.

I wonder if there is anyway to roll back to 10.11.3 outside of having an old installer app laying around.

I had the same thing happen to my iMac 5k and it ended up being the RAM. Never showed up in hardware error checker. I just swaped out a bank of ram and its been stable for 2 months now. I have had 10.11.3, and 10.11.4 (and betas) running on it. So just a thought if you want to swap RAM.

I thought about that too before I hit this thread.

But what are the chances of multiple people having bad RAM right after an update.

I'm sure its possible but hoping software issue thats gets fixed.

Don't have any spare RAM laying around that my iMac can use. 😟

I have a brand new iMac 27" 5K Retina (4GHz Intel Core i7, AMD Radeon R9 M390 2048MB with 32GB RAM, delivered feb 15.). After having some initial trouble with the iMac rebooting randomly and quite often (the reason turned out to be some corrupt RAM modules), I finally got a stable machine up and running with new RAM modules on 25. Feb.

All was fine until last week, but after updating to OS X 10.11.4 last Wednesday (23. March), the iMac started rebooting randomly again. I have witnessed the reboot once, and the machine froze for 20-30 seconds without responding, then it was like a sudden power off and a reboot with the boot sound. No error messages or apparent reason, not in the console logs either.

Since upgrading to 10.11.4 I have had 1-2 reboots a day, and all of them have been either at night or during daytime but not sitting in front of the iMac (luckily not while I was working...). I never turn the machine off, but just put it in sleep mode. When the machine reboots, it ends up back at the login prompt (not just password unlock) where one selects the user and enter the password.

Yesterday morning before I turned on the lights in the room, I noticed the iMac screen was not black as in when the computer is turned off, but rather a ”dark black but the screen is on” kind of black if you know what I mean. It didn’t respond to anything, just the beachball spinning. No response to anything, so I had to hold the on/off button to force restart it. When it had rebooted, I checked the console logs, and it had been pumping out identical GPU error messages like this one: "30.03.2016 07.49.56,974 DumpGPURestart[1115]: Saved gpuRestart report for kernel to /Library/Logs/DiagnosticReports/Kernel_2016-03-30-074956_Eivinds-iMac.gpuRestar t". But on the opther reboots I didn't have any GPU messages.

I read elsewhere that this might be a Safari problem after the 10.11.4 update (http://osxdaily.com/2016/03/26/resolving-problems-with-os-x-10-11-4/#comment-214 6338). I have only been using Safari, and usually never quit the application when letting the iMac enter sleep mode. I'm now testing to see if I get any reboots with Chrome instead (and no Safari running).

Cheers,

Eivind Rohne

I've read the same article erohne and did the test you're attempting with Chrome and Firefox independently.

Didn't seem to have an affect.

When i get home I'll parse through my logs for that GPU message to see if I get the same thing.

Hmm... I think I'll try a time machine restore to the day before I upgraded to 10.11.4. At least it had been stable for 5 weeks without any sudden reboots prior to the OS X upgrade.

Just got home and four reboots. All took place while I was asleep or at work.

Fresh install of OS X with no third party apps.

All with -128 error code.

Here is a snippet of the system log prior to boot time entry each time.

Nothing stands out...there are no entries directly prior to reboot.

Reboot 1

Mar 31 02:00:55 Kurama syslogd[40]: ASL Sender Statistics

Mar 31 02:03:21 Kurama Safari[465]: tcp_connection_tls_session_error_callback_imp 121 __tcp_connection_tls_session_callback_write_block_invoke.434 error 22

Mar 31 02:10:55 Kurama syslogd[40]: ASL Sender Statistics

Mar 31 02:15:57 localhost bootlog[0]: BOOT_TIME 1459404957 0

Reboot 2

Mar 31 02:26:00 Kurama syslogd[40]: ASL Sender Statistics

Mar 31 02:26:01 Kurama WindowServer[169]: device_generate_desktop_screenshot: authw 0x0(0), shield 0x0(0)

Mar 31 02:26:01 Kurama WindowServer[169]: device_generate_lock_screen_screenshot: authw 0x0(0)[inf, inf, 0, 0] shield 0x0(0), dev [2560,1440]

Mar 31 02:36:13 Kurama syslogd[40]: ASL Sender Statistics

Mar 31 02:43:07 localhost bootlog[0]: BOOT_TIME 1459406587 0

Reboot 3

Mar 31 02:26:00 Kurama syslogd[40]: ASL Sender Statistics

Mar 31 02:26:01 Kurama WindowServer[169]: device_generate_desktop_screenshot: authw 0x0(0), shield 0x0(0)

Mar 31 02:26:01 Kurama WindowServer[169]: device_generate_lock_screen_screenshot: authw 0x0(0)[inf, inf, 0, 0] shield 0x0(0), dev [2560,1440]

Mar 31 02:36:13 Kurama syslogd[40]: ASL Sender Statistics

Mar 31 02:43:07 localhost bootlog[0]: BOOT_TIME 1459406587 0

Reboot 4

Mar 31 16:29:48 Kurama kernel[0]: [AppleHSBluetoothDevice][getExtendedReport] Could not retrieve information for BatteryPercent feature

Mar 31 16:29:48 Kurama kernel[0]: [AppleHSBluetoothDevice][updateBatteryLevel] Couldn't get battery percentage from device

Mar 31 16:34:35 localhost bootlog[0]: BOOT_TIME 1459456475 0

I had the same issues on my iMac 5k (bought in december) prior to the 10.11.4.

My log looked like yours po09. Nothing in the log directly before the reboot. No kernel panic, no crash messages.

I also did a clean install without any config/changes or software install. Even then the machine froze for 20-30 secs before rebooting completely and ending up at the login screen.

I delivered my iMac at the service center before the easter holidays and I got a messages yesterday that they have changed both my mainboard and power supply 😐 At first they couldn't get it to reboot but after a couple of days they ordered the new parts. I think I'll have it back today so we will now if it's OK now during the weekend. Sounds strange that there is something wrong with both the power and the mainboard?! But...computers never stop surprising me 😝

I had no issues with reboots while running 10.11.2 and I think they started after the 10.11.3 release. I didn't notice them in the beginning because the machine restartet during the night. But for some weeks ago I registered that I had to select the login user. Usually I'm the only one using the machine so I just enter my password to unlock it.

I got the "Install El Capitan" app for 10.11.3 which I have made a install USB out off - but is possible to download the install app for 10.11.2 ?

Hi,

yesterday i installed 10.11.3 from my usb-stick. At first it looked good, but tomorrow morning the imac has rebooted itself again. So it seems that OS X 10.11.3 does not resolve this issue. I guess i will contact the apple support now.